Heat exchanger

Abstract

A heat exchanger has a shell formed of several sections placed side by side and each defining an intermediate baffle forming part of a spiral surface. The adjacent sections define together a spiral path extending through the shell in the direction of its axis. Tubes extend in this axial direction through aligned holes provided in each shell section. The tubes communicate between end spaces comprising an inlet and outlet for the first fluid. The use of shell sections provides a convenient construction method for the heat exchanger while the spiral path for the second fluid gives better flow characteristics.

What is claimed is:  
     
       1. A shell and tube type heat exchanger comprising a single outer tubular shell containing a spiral baffle path defied by a spiral baffle through which a tube bundle extends in a direction generally parallel with the longitudinal direction of the tubular shell, the heat exchanger comprising an assembly of a plurality of heat exchange elements each of which comprises a shell section which forms part of an axial length of the shell and a spiral section which forms part of a length of the spiral baffle path. 
     
     
       2. A shell and tube heat exchanger according to  claim 1 , wherein the shell and spiral sections are integrally formed by casting or moulding. 
     
     
       3. A shell and tube heat exchanger according to  claim 1 , wherein the spiral section is secured to a central member. 
     
     
       4. A shell and tube heat exchanger according to  claim 3 , wherein the spiral section is integrally formed with the central member by casting or moulding. 
     
     
       5. A shell and tube heat exchanger according to  claim 3 , wherein the central member is in the form of a rod or tube. 
     
     
       6. A shell and tube heat exchanger according to  claim 1 , wherein the spiral section is a spiral baffle plate in the form of a single curved sheet which executes at least one complete turn. 
     
     
       7. A shell and tube type heat exchanger according to  claim 1 , wherein a region of the shell extends around the whole periphery thereof, and is inwardly or outwardly deformed to allow differential expansion between the shell and tube bundle. 
     
     
       8. A shell and tube heat exchanger comprising: 
       a single elongate tubular shell having a tubular elongate shell intermediate portion made up only of a plurality of shell sections, each section comprising a tubular wall portion and a spiral portion within the tubular wall portion, the shell sections being assembled side-by-side along an axis of the tubular shell and connected one to another for said tubular wall portions to define the outer wall of said shell intermediate portion and for said spiral portions to define a spiral path extending around and along the axis of said shell intermediate portion;  
       two shell end portions connected to respective ones of the ends of said shell intermediate portion; and  
       a plurality of tubes extending between said shell end portions and through respective apertures in said spiral portions.  
     
     
       9. The shell and tube heat exchanger according to  claim 8 , wherein each spiral portion defines a single complete turn. 
     
     
       10. The shell and tube heat exchanger according to  claim 8 , wherein the spiral portion of each shell section defines the same number of turns.